Camera-plate holder for holding negative-paper



(No Model.)

T. H. BLAIR.

CAMERA PLATB HOLDBR FOR HOLDING NBGATIVE PAPER.

No. 370,370. Patented Sept. 27, 1887.

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THOMAS H. BLAIR, OF BOSTON, MASSACHUSETTS.

CAMERA-PLATE HOLDER FOR HOLDING NEGATIVE-PAPER.

SPBCIFICA'I'ION forming part of Letters Patent No. 370.370, datedSeptember 2'7, 1887.

. Application filed July 23, 1887. Serial No. 245,136. (No model.)

To aZZ whom it may concernz Be it known that I, THoMAs H. BLAIR, acitizen of the United States, and a resident of Boston, in the county ofSuflolk and State of Massachusetts, have invented new and usefulImprovements in Camera-Plate Holders for Holding Negative-Paper, ofwhich the following, taken in connection with the accompanying drawings,is a specification.

This invention relates to improvements in plate-holders for holdingnegative-paper, and it is carried out as follows, reference being had tothe accompanying drawings, where- Figure 1 represents a front elevationof the invention, showing a portion of the slide as removed. Fig. 2represents a Vertical section on the line A B, shown in Fig. 1. Fig. 3represents a cross-section on the line O D, also shown in Fig. 1; andFig. 4 represents an enlarged longitudinal section of the plate to whichthe negative-paper is attached.

Similar letters refer to similar parts wherever they occur on thedifferent parts of the drawings.

The plate-holder frame is composed of the side pieces, a a, the bottompiece, a', and top or head piece, a, as shown, secured together in sucha manner as to form a square or rectangular inclosure that is. open fromfront to rear, and is without any stationary diaphragm or division-wall.The head a is slitted for the reception of the slides b 1),, which areguided in grooves in the interior portions of the bottom and sidepieces, a' a a, as is common in camera-plate holders.

b b3 are the bars or handles, secured in a suitable manner to the upperproject-img ends of the slides b b', as shown in Figs. 1 and 2.

cin Figs. 2, 3, and 4 is the plate to which the sheet of negative-paperd is temporarily secured, and for this purpose I make a slit or groove,c', in one end or side of such plate o, as shown in upper end of Fig. 4,and in such slit I introduce one end of the negative-paper d, which isafterward wrapped smoothly around the two opposite sides of the saidplate c and carried far enough to lap over the slittedportion c', asshown in Fig. 4, thus providing the plate c with a sensitivenegative-paper surface on two of its sides for the taking of twodifferent exposures.

To the interior portion of the bottom piece,

a, of the plate-holder frame I secure a metal spring, e, forlholding theplate c in positionv when introduced in the plate-holder, as shown inFigs. 1 and 2.

At the junction of side pieces, a a, and bottom piece, a, I insert inmiter slits made through such parts the venecrs f and a portion of whichprojects inside of the parts a a and a' and serves as guides betweenwhich the lower end of the plate c is inserted and held in its properplace, as shown in Figs. l, 2, and 3.

Between the slides b and b', I make on the interior of the frame a a a',nearest to the slide b', a rib or projection, af, that serves as arigidbed or support for the plate o when inserted within the holder, as shownin Figs. 2 and 3, and the said bed or rib a* also serves to prevent thelight on the side of the negative-paper that is being exposed frompassing to the opposite side of such negative-paper.

In a slit in the under side of the top piece, a', of the plate-holderframe I secure a pair of flexible cloth or rubber fiaps, g g, (shown inFig. 2,) which, when the slides are drawn,

,serve to close the slits in the top piece, w, as

is common in plate-holders.

h h are suitable packings arranged in grooves in' the head or top piece,a', for preventing the light from entering through the slits in the saidtop piece, ct', when any of the slides are drawn out in theusualvmanner.

In using this my improved plate-holder I proceed as follows: Afterhaving secured the negative-paper d to the two opposite sides of theplate c, I draw out the slide b and insert the lower end of the plate cin the space between thelower projections, f f ',with its lower edgeresting on the yielding spring e, and depress the latter until the upperend of the plate c will pass below the interior lower portion of the toppiece, a', when I press the plate c into the holder until one of itssides is made to rest against the rib or ridge af, as shown in Figs. 1,2, and 3, when the plate c will be held firmly in position, as shown inFigs. 1 and 2, by the spring e pressing its upper end with a properfrictional resistance against the under side of the head a', after whichthe slide b is closed, as shown.

In this manncr I produce a very light and durable double plate-holderhaving a central rco plate provided with sensitve negative-paper on twoof its opposite sides, as shown and described. After the negative-paperhas been exposedin a camera as usual and the plate-holder taken to thedark room, IWithdraw the sldes b b' and remove the platec and its paper(Z simply by moving the upper end of said plate a little to the left (inFig. 2) until it comes to one side of the head-piece a', after which itcan easily be drawn out of the plate-holder and the paper removed fromthe plate c and another strip put on it, and so on.

Having` thus fully described the nature, construction, and operation ofiny invention, I Wish to secure by Letters Patent, and elaim- 1. Inaplate-holder for negative-paper, the plate c, having a slit, of, in oneof its ends or sides adapted to receive one of the ends of thenegative-paper d, combined With the latter Wrapped around it, as and forthe purpose set forth.

2. rhe frame a a a' a, open from side to side and provided With thesldes Z) b', and having` lower guides, ff', the rest or rib at, andspring a, combined with the detaehable plate c, having` a slit, c', inone of its sides or ends for seeuring to it the negative-paper (Z, asand for the purpose set forth.

3. The frame a a a' a, open 'from side to side and provided With slidesZ) i), combined With the deta-ehable plate o, upon which the negative-paper is Wrapped orsecured on both sides of said plate, for thepurpose set forth.

In testimony whereof I have signed my name to this specification, in thepresenee of two subseribing witnesses, on this 12th day of July, A, D.1887.

THOMAS H. BL AIR.

'Witnessesz ALBAN ANDRN, HENRY CHADBOURN.

